Recommended classes in the Meteoritical Bulletin Database are assigned by the database editor. In most cases, this is based on the most recent classification that appears in either the Catalogue of Meteorites, MetBase, the US Antarctic Meteorite Newsletter, the Japanese Meteorite Newsletter, or the Meteoritical Bulletin. However, in a few cases it reflects differences of opinion about the proper way to classify the meteorite. The nomenclature used may also be modified by the editor to conform to an internally consistent classification scheme
The recommended classification E5-an means:
"An enstatite chondrite of petrologic type 5 with anomalous properties that has not yet been classified into any group."
The highlighted words are defined as follows:
enstatite chondrite: A major class of chondrites that mostly have sub-solar Mg/Si and refractory/Si ratios, oxygen isotope compositions that plot near the terrestrial fractionation line, and highly reduced mineral assemblages (containing little FeO, Si-bearing metal, and sulfides of elements normally considered lithophile).
type 5: Designates chondrites that have been metamorphosed under conditions sufficient to homogenize olivine and pyroxene, convert all low-Ca pyroxene to orthopyroxene, cause the growth of various secondary minerals, and blur chondrule outlines.
anomalous: Designates meteorites that have been determined to be a member of a specific group, but have certain properties that are unusual or distinctive.
Find all meteorites of type: E5-an